Have puma-dev proxy the requests through to the node server perhaps? Similar to what i guess you were trying worh Caddy github.com/puma/puma-de...

puma-dev also deals with creating https certificates for the local domains, and can proxy requests through to non-puma http servers, so might be just the thing you need

puma-dev solves this for me - it includes the tiny DNS server needed to resolve subdomains and you can configure it to work with *.localhost.

I find it more annoying that editing an localhost url in the address bar will often turn into a web search instead of going to the new address.